As a conventional method of cooling an electronic part represented by a LSI packaged on electronic equipment or power equipment, as described in, e.g., Japanese Unexamined Patent Publication No. 6-21279, there has been known a method of radiating heat generated from a heat-generation member such as the LSI by combining a refrigerant bag and a heat pipe to each other.
Prior Art FIG. 19 is a view of the arrangement of a conventional heat-transfer apparatus described in Japanese Unexamined Patent Publication No. 6-21279.
Referring to FIG. 19, a protection metal vessel 1 has a hole portion 2 formed in a bottom portion thereof. A refrigerant bag 3 is stored in the lower portion of the protection metal vessel 1. The refrigerant bag 3 has an arrangement in which both the ends of a cylindrical member consisting of a soft plastic material such as polyethylene are sealed by means of heat fusing or the like, has an operation liquid 4 filled therein, and has a gas filled in the upper space thereof. When the refrigerant bag 3 is stored in the protection metal vessel 1, the refrigerant bag 3 partially projects from the hole portion 2 to form a contact portion 5 which is brought into contact with a target object 8 such as a LSI.
A heat-transfer pipe 6 is stored to be wrapped with the refrigerant bag 3, and a heat-radiation fin 7 is attached to one end of the heat-transfer pipe 6 which projects outside the protection metal vessel 1.
A halogen-based refrigerant such as flon or p-fluorocarbon (C.sub.6 F.sub.14) is used as the operation liquid 4.
An operation of the conventional heat-transfer apparatus will be described below.
The heat-transfer apparatus is installed such that the contact portion 5 is brought into contact with the target object 8 such as the LSI. Heat generated by the target object 8 is transferred from the contact portion 5 to the operation liquid 4. The operation liquid 4 is evaporated by the heat transferred from the contact portion 5, and the vapor condensed at the portion where the vapor is in contact with the heat-transfer pipe 6 in the refrigerant bag 3 to be liquified and dropped. With this exchange of latent heat, the heat is absorbed by the heat-transfer pipe 6. Thereafter, the heat is radiated from the heat-radiation fin 7 attached at one end of the heat-transfer pipe 6. When such heat exchange is repeated, the target object 8 is cooled.
Since the conventional heat-transfer apparatus is arranged as described above, the target object cannot be cooled to a temperature which is equal to or lower than the outer temperature of the heat-radiation portion. The use environment of the heat-transfer apparatus is disadvantageously limited.
Since a halogen-based refrigerant such as flon or p-fluorocarbon is used as the operation liquid 4, when the apparatus is scrapped, the refrigerant must be retrieved form the apparatus for environmental protection. However, in general, many electronic equipments frequently have an unspecified number of markets as targets. Therefore, a problem caused by the retrieving method must be solved.
General electronic equipment is necessarily decreased in size, the structure of the above heat-transfer apparatus cannot be decreased in size. Therefore, a sufficient means for the decrease in size cannot be made.